[Frisk x Sans] Frisk has been preparing to marry into the monster royal family since she was a child. Her only escape from her princess-ly duties is a computer game called UnderLook, a multiplayer team-based smash hit game with a cult following. Online, she made a friend. What would he think if he knew she was going to be a princess?

You are a young woman in search for a place to live outside the dorms of the University you've been accepted to. Finding an ad in the paper while searching, you find a manor that is offering a very affordable room and is run by monsters. Only problem is they are looking for male applicants only. Includes, from the original duo, swapfell, underfell, underswap bros! Sans/Reader/Papy

When Sans was injured so badly he had to be hospitalized, Papyrus thought that was the worst thing to have happened to either of them. But while cleaning Sans's room he found something he'd never seen before, now Papyrus is questioning everything he ever thought he knew about himself or Sans. Underfell AU, Mpreg.

Frisk is imprisoned in an inescapable hell above the surface with her children and her only friend in the world, Flowey. She should be there for the rest of her life. That is until the day the monsters learned the truth about the 'Pacifist Child', then Asgore receives a peace offering he can't refuse. (Romance eventually, Sans/Frisk.)

The misadventures of Sans and Frisk. After Sans makes the decision to ultimately become human, he ends up asleep for five years. When he wakes, Frisk is an adult. Both love each other, but through trial and tribulation they must learn both how to handle a world with many diverse creatures, and learn what it means to be human

(Open Deviant Art Chat-room; #AnatomyUndertaleFF) Frisk has spent many years underground with her monster friends, all is well in the world under the mountain. Well..until her monster friends start wanting to now more about Frisk. And some skeletons are a bit or nosey than others. Some videos that fall into the Underground aren't very accurate of Human Anatomy.